I've never seen a software which can do this in realtime.
With ArchiCAD and Teamwork/BIM Server you can work on the same project,
but you can't see realtime what your partner is drawing. The sync must be started manual, so that there is a delay of some minutes.

Maybe a good alternative is desktop sharing with f.e. teamviewer.

A combination of both should be very comfortable. When you discuss some
points you do this with desktop sharing and in the meantime you work on the same project.